Angiography is a type of X-ray used to examine blood vessels. The images created during an angiography are called angiograms.
Blood vessels don't show up clearly on ordinary X-rays, so a special dye is injected into the area being examined. The dye highlights the blood vessels as it moves through them and appears white on the angiogram. The medical name for this type of angiography is cardiac catheterisation.
Less commonly, angiographies can also be carried out using magnetic resonance imaging (MRI) scan and computerised tomography (CT) scan techniques.
Why angiograms are used
Angiography can help diagnose conditions that affect blood vessels and the flow of blood through them. These include:
Problems caused by serious arterial disease include strokes, heart attacks, gangrene and organ failure, so it's important that problems with your circulation are investigated as soon as possible.
The images from coronary angiography are important to help plan treatment for angina and heart attacks. Treatment options include medication or surgery, such as a coronary angioplasty or a coronary artery bypass graft.
The angiography procedure
Angiography is carried out in hospital. It takes between 30 minutes and two hours, depending on the complexity of the investigation. You will usually be allowed to go home on the same day, although in some cases you may need to stay in hospital overnight.
In most cases, angiographies are planned procedures performed under local anaesthetic, sometimes with sedation. However, general anaesthetic may be used for young children or if the procedure is particularly complex.
A very thin flexible tube called a catheter is inserted through a small cut and into one of your arteries, usually in your groin or your leg. A radiologist (a doctor who specialises in imaging studies) will guide the catheter into the area that needs to be examined. The dye (medically known as a contrast dye or contrast medium) is injected through the catheter and into the blood vessel. A series of X-rays is then taken.
Read more about what happens during an angiography.
Angiography is generally a safe and painless procedure. The risk of serious complications is low.
Sometimes it can cause minor bruising where the catheter is inserted. Also, some people may occasionally have an allergic reaction to the contrast dye. This is usually easily treated with medication.
Read more about the complications of an angiography.